This invention relates generally to a method of separating copper from a low grade copper ore and, more specifically, a wet method for the lixivation of copper from chalcopyrite.
In the separation of copper from a high grade copper ore such as chalcocite CuS.sub.2, covellite CuS or bornite Cu.sub.5 FeS.sub.4, a dry method is generally adopted. Because of a high energy cost, the dry method is not employed for the separation of copper from a low grade copper ore such as chalcopyrite (CuFeS.sub.2). It is well known in the art that copper cannot be leached out from chalcopyrite with an acid alone. Thus, a method is proposed in which the lixivation is carried out using an aqueous sodium chloride solution containing cupric chloride as an oxidation agent. Also known is a wet method in which an aqueous ferric chloride solution is used as a lixivation liquid. The former method is, however, disadvantageous because copper is used for the lixivation of copper. The latter method has a problem that the a large amount of ferric ion is present in the leached product.